Odd issue when replacing rear wheel bearing.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Prius92, Oct 16, 2025.

  1. Prius92

    Prius92 Active Member

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    I've never had to disconnect the 12v battery when I did the fronts, are you supposed to for the rear?

    I replaced the bearing and the ABS and brake lights came on. I never touched the power button while working on it.
    Took it to autozone and the code was for the wheel speed sensor.

    I was irritated thinking the brand new bearing had a bad sensor.
    So I unplugged the battery for 30 minutes, and while doing that, I hooked an oscilloscope to the speed sensor on the new bearing and saw it make a waveform.

    Hooked battery back up and the light is STILL on. So I go back to autozone and they check it again and...there aren't any codes.
    So he asks if he can reset the lights and I'm like go for it. He does and they have not been back on since.

    I've never seen the ABS / brake light remain on without any codes present.
     
    #1 Prius92, Oct 16, 2025
  2. Brian1954

    Brian1954 Senior Member

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    The Autozone scanner was not capable of reading all the trouble codes that the car had, but it was capable of clearing the codes. Read post #1 in this thread.

    There is a good chance that the warning lights will return.
     
    #2 Brian1954, Oct 16, 2025
  3. ChapmanF

    ChapmanF Senior Member

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    That's what I was about to write, but I saw in the second paragraph of post #1, that was also at Autozone and the scanner displayed the code.

    Could it be maybe on two trips to Autozone, two different scanners got used?

    Hey, who's supposed to read post #1 anyway? Isn't the the post being replied to in post #2?
     
    #3 ChapmanF, Oct 16, 2025
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